DETROIT -- For daily marijuana users seeking relief from nausea, doctors now say that using too much for too long can have the opposite effect in rare cases — triggering abdominal cramping, vicious vomiting and an overwhelming urge for a hot shower.

Yes, a shower.

In cases of cannabinoid hyperemesis syndrome, doctors theorize that the active ingredient in marijuana, THC, overwhelms the body's autonomic nervous system, which normally controls breathing and digestion and other automatic functions, said Dr. Cassius Drake, medical director of the emergency department at Henry Ford Health Center-Brownstown.

That leads to a condition that has been likened to the morning sickness associated with pregnancy, said Susan Smolinske, managing director at the Children's Hospital of Michigan Regional Poison Control Center.

"Marijuana typically causes the munchies, right? This is the anti-munchies," she said.

And a sufferer's scramble for the tub?

"The thinking is that a hot shower gives some feedback that resets temporarily the autonomic system," Drake said.

Identified only in recent years, the condition seems to be rare, affecting only long-term daily users, according to medical literature.

At the Kalamazoo-based Michigan Holistic Health, clinicians have seen no cases among about 13,000 clients, said registered nurse Annette Crocker who, with her husband, Dr. David Crocker, runs the clinic.

Paul Armentano, deputy director of the Washington-based National Organization for the Reform of Marijuana Laws (NORML), said reported cases most likely have to do with a malfunction of the patient's internal system, not because of the marijuana, which has been used for years to settle queasy stomachs.

"Cannabis has a long history as an antiemetic agent," he said.

Still, poison control officials have been called at least five times since mid-May about marijuana users being severely nauseous and vomiting, Smolinske said.

At Henry Ford, Drake said he diagnosed his first case in recent weeks.

More cases may be reported as Michigan doctors see more medical marijuana users under the state's 5-year-old medical marijuana law, Drake said.

Though the condition isn't deadly, it can be expensive. If doctors don't recognize it, they might order CT scans, X-rays, ultrasounds, blood screenings — the types of tests that can run into tens of thousands of dollars, Drake said.